The present invention relates to an ultrasound inspection device, an ultrasound image data generation method, and a recording medium in which is stored a program, which capture an image of an object to be inspected, such as an organ within the body or the like by transmitting and receiving an ultrasonic beam, to generate an ultrasound image used for examining and diagnosing the object to be inspected.
Conventionally, ultrasound inspection devices such as ultrasound imaging and diagnostic devices using ultrasound images are used in the medical field. Normally this type of ultrasound inspection device includes an ultrasound probe that contains a plurality of elements (ultrasound transducers), and a device body connected to the ultrasound probe, the plurality of elements of the ultrasound probe transmits an ultrasonic beam towards the object to be inspected (inspection object), and receives the echoes of the ultrasonic wave from the inspection object at the ultrasound probe, and by electrically processing the received ultrasonic echo signals in the device body, an ultrasound image is generated.
In an ultrasound inspection device, when generating an ultrasound image, the ultrasonic beam is transmitted with the focal points of the plurality of elements of the probe focused on the area to be examined in the inspection object, for example, an organ within the body or a lesion within that organ or the like, and the ultrasonic echoes from reflectors in the inspection object, for example the surface or boundary of the organ or lesion or the like, are received by the plurality of elements, but the ultrasonic echoes reflected from the same reflector are received by the plurality of elements, so the ultrasonic echo signals reflected by a reflector located at the focal position of the ultrasonic beam transmitted from the transmitting element and received by an element that is different from the transmitting element may be delayed with respect to the ultrasonic echo signal received by the transmitting element, so after the ultrasonic echo signals received by the plurality of elements are subject to analog to digital (A/D) conversion to become element data, receiving focus processing is carried out on the element data, in other words sonic signals are generated by correcting delays and phase addition is carried out to align the phases, and the ultrasound image is generated based on these obtained sonic signals.
In this ultrasound inspection technology, in order to improve the image quality of the ultrasound images, the signal quality is improved compared with the conventional technology by adding signals transmitted with a plurality of different focal points.
For example, in JP 2009-240700 A, a virtual point sound source is formed by focusing a transmitted ultrasonic wave emitted from a plurality of vibration elements that compose a transmission vibration element group onto a transmission focal point, then, the received ultrasonic waves reflected from a plurality of continuous measurement points as a result of the transmission ultrasonic wave emitted from this point sound source are received by a plurality of vibration elements that compose a receiving vibration element group, and phase addition is carried out on the reception signals for the channels obtained to form the receiving focusing point of the measurement point. In addition, an ultrasound diagnostic device is disclosed that carries out transmission phase addition in which the same phase addition is carried out on reception signals obtained using each transmission element group that has been successively shifted in the direction of the array of the vibration elements of the transmission vibration element group, and corrects the transmission delay time caused by the difference in each propagation distance from the transmission focal point to the measurement point for the reception signals after this receiving phase addition.
In JP 2009-240700 A, it is possible to forma transmission beam and receiving beam having a virtually uniform fine beam width in the depth direction of the inspection object with high accuracy and high sensitivity, by carrying out the receiving phase addition and the transmission phase addition on the reception signals obtained from the plurality of vibration elements. Therefore, JP 2009-240700 A discloses how to generate and display image data with excellent spatial resolution, contrast resolution, and S/N ratio (signal-noise ratio).